$ perl -MO=Concise -pe '$_=split "foo"' >1.txt
-e syntax OK
$ perl -MO=Concise -pe '$_=split /foo/' >2.txt
-e syntax OK
$ diff [12].txt
20c20
< 6                          </> pushre(/"foo"/) s*/64 ->7
---
> 6                          </> pushre(/"foo"/) s/64 ->7